This invention relates to a grinding device which is such that abrasive materials and worked pieces are thrown into grind tubs and the grind tubs are rotated or oscillated by a fly-wheel and a turret plate to grind and process the worked pieces.
Japanese Patent No. 2,984,996 by this applicant discloses a grinding device 101 as shown in FIGS. 8 through 11.
The grinding device 101 is constituted of both side plates rotating at a desired speed, namely a fly-wheel 102 and a turret plate 103, grind tubs 105 held between the fly-wheel 102 and the turret plate 103, and cover portions 110 each of which closes an opening portion 106 of the grind tub 105.
The turret plate 103 is formed in a cross shape with four leg portions 104 extending in a radial direction thereof Four grind tubs are provided between the leg portions 104 and the fly-wheel 102 rotatably or oscillatably. Furthermore, when one of the leg portions 104 is at a position extending in a horizontal direction, a peripheral portion 107 of the opening portion 106 is positioned above the leg portion 104 extending in the horizontal direction as shown in FIG. 9, so that installation of the cover portion becomes possible.
The cover portion 110 is provided with spacer plates 112 formed unitedly on a peripheral portion 111 in a surface side thereof, and each of the spacer plates 112 positioned backward in an attaching direction of the cover portion 110 is provided with a lack portion 113 at an end portion forward of the attaching direction in the spacer plate 112.
Each of cams 108 has a lower surface formed in an arc shape, a convex guide hook 109 is projected and formed at an end portion forward in the attaching direction of the cover portion 110. The cams 108 is slanted so that each lower portion of the cams is positioned backward in the attaching direction before installation of the cover portion 110 as shown in FIG. 11. When the cover portion 110 is installed on the grind tub 105, the leg portion 104 on which the grind tub 105 is held is made to move at a horizontal position, and then the cover portion 110 is made to arrange a peripheral portion 107 of the grind tub 105 so that an end portion of each spacer plates 112 of the cover portion 110 comes to be in contact with the convex guide hook 109 of each cam 108, the cover portion 110 sliding on the peripheral portion 107 of the grind tub 105. Thereupon, the cams 108 rotate along the spacer plates 112, as shown in FIG. 12, and then the cams 108 are made to erect on the spacer plates 112 to press the spacer plates 112, as a result, the cover portion 110 may close the opening portion 106 of the grind tub 105.
Each leg portion 104 attached on the grind tub 105 into which the abrasive materials and the worked pieces are thrown is mode to move to the horizontal position in t and then the cover portion 105 is installed to the grind tub 105 moved to the horizontal position in turn. After that, the fly-wheel is made to be rotated in order to rote or oscillate the grind tub 105, as a result, the worked pieces may be grinded by colliding the abrasive materials and the worked pieces in the grind tub 105.
As explained above, in Japanese Patent No. 2984996 by this applicant, as the turret plate is formed in a cross shape, the cover portion can be installed on the opening of the grind tub by sliding the cover portion, thus, reduction of a setting space necessary to the whole of the grinding device can be designed. Furthermore, because the cover portion is slide to be installed to the grind tub, work for installing the cover portion to the grind tab is made to be an automation, as a result, number of man-hour of a whole work can be decreased.
However, in the above patent, since the turret plate is a cross shape, total weight of the grind tub, the abrasive materials and the worked pieces thrown into the grind tub must be limited in a strength problem.
An object of this invention is to increase strength of the turret plate and to disclose new constitution of a cover portion.
Accordingly, this invention is a grinding device comprising: a rotatable fly-wheel; a turret plate which is located face to face with the fly-wheel and rotates in synchronization with the fly-wheel, the turret plates being formed in a cross shape with four legs extending in a radial direction thereof; four grind tubs located rotatably or oscillatably between the fly-wheel and vicinities of front ends of the legs of the turret plate, each of which has an opening portion above thereof a periphery portion of the opening portion in the grind tab provided on the leg at a position extending horizontally positioning above an horizontal upper edge of the leg; a cover portion installable to the opening portion of the grind tub by sliding; a fix means provided between the cover portion and the grind tub; and a reinforcement means provided on the turret plate.
Furthermore, it is desired that the reinforcement means is a reinforcement plate installed on the turret plate, the reinforcement plate being the same shape as the turret plate. Moreover, it is desired that the reinforcement plate is fixed on the turret plate with a specific distance to the turret plate. Also, it is desired tat each of bearings arranged between the reinforcement plate and the turret plate is provided on a shaft which holds the grind tub to the turret plate and extends between the reinforcement plate and the turret plate to hold a space between the turret plate and the reinforcement plate.
Furthermore, the fix means comprising: a flange portion formed on a periphery of the opening portion in the grind tub; a plurality of fixed pieces extending from specific positions in two side edges along a cover portion sliding direction and facing a lower surface of the flange portion; elliptical fixing members located below the flange portion, which are positioned between said fixed pieces and the flange portion when the cover portion has bee installed on the grind tub, the fixing members being fixed eccentrically on rods extending in the sliding direction; wherein the fixing members press the fixed pieces below by rotating the rods to fix the cover portion to the grind tub, the fixing members separating from the fixed pieces by rotating the rod to release fix of the cover portion.